1. Field of the Invention
The present invention relates generally to an apparatus for inhibitively preventing birds such as pigeons or the like from crowding at the upper part of a building such as a veranda or the like. More particularly, the present invention relates to improvement of an apparatus of the foregoing type.
2. Description of the Related Art
In recent years, the number of birds such as pigeons, crows, sparrows, gray starlings or the like living in a city increases but droppings and infectious bacilli discharged from birds become a serious problem from the viewpoint of environmental sanitary. In view of the foregoing fact, various proposals have been made with respect to an apparatus for inhibitively preventing birds such as pigeons or the like from crowding inside of a veranda or a similar location on a building by utilizing, e.g., needles, supersonic sound, rapacious bird eye-like convexly marks or the like. In addition, another proposals have been made with respect to an apparatus of the foregoing type in significant consideration of the fact that each bird dislikes the presence of a high intensity of magnetic field because the biological instinctive ability of each bird for sensing the magnetic field (effective for determining the direction of his flying or maintaining an instinct of returning to his home position by himself) is adversely disturbed by the magnetic field. In this connection, it is recommendable that reference is made to an official gazette of, e.g., Japanese Utilization Model Publication NO. 4-10789 which discloses a typical apparatus of the aforementioned type.
However, this conventional apparatus has the following problem. Specifically, a plurality of semispherical magnets arranged along a tension wire in the substantially equally spaced relationship as seen in the horizontal direction exhibit a function of preventing pigeons from crowding on the tension wire to some extent but some pigeons are not sensitive to the magnetic field, causing them to perch still on the tension wire between adjacent magnets. For this reason, the foregoing proposed apparatus is not satisfactorily acceptable for any user.
In addition, a proposal has been made by an applicant common to the present invention with respect to an apparatus for inhibitively preventing birds from crowing at the upper part of a building wherein the apparatus is constructed such that a pair of support columns are caused to stand upright from the handrail of a veranda, a wire is tightly spanned between both the support columns, and a plurality of magnetic members are arranged along the wire in the spaced relationship for the purpose of preventing birds from perching on the veranda (see the specification of Japanese Utilization Model Application NO. 4-93897).
It is certain that this proposed apparatus is effective for preventing pigeons from perching on the handrail of the veranda. However, in the case that the veranda has a large width, it is necessary that many apparatuses each constructed in that way are mounted on the veranda. When birds invade directly in a room through a window, the proposed apparatus not always exhibits its own function.
To cope with the foregoing problem, it is thinkable that all the opening portions on a building are covered with a net or a similar material. However, at the time of an occurrence of emergency such as firing or the like, the net becomes a kind of obstacle not only for persons who want to escape from their room but also for firemen who should enter the room for performing a fire fighting operation.